External Battery Case or Another Battery for Replacement ?

[bigwig]

I am in researching for a extenal power for long standby time with my S3, but purchase a replacement battery Samsung Galaxy S3 Battery, (PISEN) Lithium-ion Battery for Samsung Galaxy S3 i9300 - TinyDeal or a battery case 3200mAh Rechargeable Power Case for Samsung Galaxy S III MBT-110319 - TinyDeal?
Bring another battery for replacement seems not as convinient as a battery case, and this battery case has a higher capacity of 3200mAh.
Hesitating on this decision!

[spodoc]

I have a 8000 and 7000 mah ext packs. Love them. 7000
Has 2 USB ports. One can do 2 a for iPad. Very nice to have. Amazon or buy has them for < 50$

[gordhunt]

I keep a charger with a spare battery (factory kit) in my truck and just swap battery when needed. Works great and always have a fresh battery if needed. Phone boots so fast its not a big deal to swap it out try doing that with an iphone lol

Sent from my Galaxy S3

[bigwig]

I keep a charger with a spare battery (factory kit) in my truck and just swap battery when needed. Works great and always have a fresh battery if needed. Phone boots so fast its not a big deal to swap it out try doing that with an iphone lol

Sent from my Galaxy S3

This is better choice I think finally